HyperVM is the no cost alternative.
Virtulizor (from Softaculous) is also worth looking at.
I would personally not go for the former, but many small companies have built a business from this.
We used to use SolusVM, but moved away due to the lack of progress seemingly made on verson 2.
Now SolusVM are owned by Virtuozzo, not sure what's in store for them, they could go either way.